Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a stack-based buffer overflow exists in the copydir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library's renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de->d_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system.
Metrics
Affected Vendors & Products
References
History
Fri, 14 Aug 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Netatalk
Netatalk netatalk |
|
| Vendors & Products |
Netatalk
Netatalk netatalk |
Fri, 14 Aug 2026 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a stack-based buffer overflow exists in the copydir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library's renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de->d_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system. | |
| Title | Netatalk has Integer Underflow → Stack Buffer Overflow in copydir() | |
| Weaknesses | CWE-191 | |
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-14T19:06:22.102Z
Reserved: 2026-05-13T04:38:01.165Z
Link: CVE-2026-45699
No data.
Status : Received
Published: 2026-08-14T19:17:18.267
Modified: 2026-08-14T19:17:18.267
Link: CVE-2026-45699
No data.
OpenCVE Enrichment
Updated: 2026-08-14T21:15:06Z